How do you make linked duplicates with modifiers?
For the moment you can give a modifier to a linked duplication but you won't be able to apply it (unless you make it a single object of course). So what you're looking for is probably Collecion Instance.
Create Your object (or your objects), put it in a new collection:

Press ShiftA &gt; Collection Instance and choose the collection. By default it will appear where the original object is relatively to the world center, so move the instances away:

If you give your original object a modifier, they will all be affected, you can also apply the modifier:

If you ever need to make one of the instance independent, select and press CtrlA &gt; Make Instances Real, then Object &gt; Relations &gt; Make Single User &gt; Object &amp; Data.